Entire corpus callosum and diffuse white matter involvement in acute Marchiafava-Bignami disease.

Acute Marchiafava-Bignami disease (MBD) can extend beyond the corpus callosum to diffuse hemispheric white matter, portending poor outcomes. We report a 57-year-old man with long-standing alcohol abuse who developed weakness and coma. Magnetic resonance imaging (MRI) revealed hyperintense, swollen lesions throughout the corpus callosum and extracallosal white matter on T2-weighted imaging (T2WI)/fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging(DWI), consistent with cytotoxic edema. Despite prompt high-dose thiamine and aggressive supportive care, he died within days. This case underscores the diagnostic value of DWI for early detection and prognostication in acute MBD, and highlights the importance of urgent brain MRI in comatose patients with a background of chronic alcohol abuse.